Automatic lens design and manufacturing system

ABSTRACT

The present invention provides a method for designing and making a customized ophthalmic lens, such as a contact lens or an intraocular lens, capable of correcting high-order aberrations of an eye. The posterior surface of the customized contact lens is designed to accommodate the corneal topography of an eye. The design of the customized ophthalmic lens is evaluated and optimized in an optimizing routine using a computational model eye that reproduces the aberrations and corneal topography of an eye. The present invention also provides a system and method for characterizing the optical metrology of a customized ophthalmic lens that is designed to correct aberrations of an eye. Furthermore, the present invention provides a business model and method for placing an order for a pair of customized ophthalmic lenses.

This application is a national stage filing under 35 U.S.C. 371 ofInternational Application No. PCT/EP02/04649 filed Apr. 26, 2002, whichclaims benefits of U.S. Provisional Patent Application Nos. 60/287,189filed Apr. 27, 2001 and 60/313,898 filed Aug. 21, 2001.

FIELD OF THE INVENTION

The present invention relates to a system and method for designingand/or producing a customized ophthalmic lens, in particular anophthalmic lens capable of correcting high order monochromaticaberrations of eyes. In addition, the present invention discloses amethod and system for creating an individualized computational model eyeuseful for evaluating/optimizing the optical design of an ophthalmiclens capable of correcting high order monochromatic aberrations, amethod and system for creating and producing stock keep units ofophthalmic lenses capable of correcting high order monochromaticaberrations of an eye, a system and method for manufacturing anophthalmic lens which is capable of correcting high order monochromaticaberrations, a system and method for characterizing the metrology ofophthalmic lenses, and a method for placing an order of a customizedophthalmic lens.

BACKGROUND

There has been and continues to be a need to provide an individual withimproved visual acuity or visual benefit. One of known solutions is touse contact lenses in correcting adverse vision conditions. Currentcontact lenses have a relatively simple surface design and generally arerotationally-symmetric or toric. These contact lenses are able tocorrect low-order aberrations of the human eye, such as defocus,astigmatism and prism. For people who only have these low-ordermonochrmoatic aberrations of the eyes, their visual acuity can beimproved to 20/20 or better by wearing current contact lenses. However,current contact lenses are unable to correct high-order monochromaticaberrations of the human eye, such as a non-standard amount of sphericalaberration, coma, and other irregular high-order aberrations. These highorder aberrations blur images formed on the retina, which can impairvision. The impact of these higher-order aberrations on retinal imagequality can become significant in some cases, for example, in oldereyes, in normal eyes with large pupils, and in the eyes of many peoplewith irregular astigmatism, keratoconus, corneal dystrophies, postpenetrating keratoplasty, scarring from ulcerative keratitis, cornealtrauma with and without surgical repair, and sub-optimal outcomefollowing refractive surgery. For those people, visual acuity of 20/20or better can be achieved with customized contact lenses or contactlenses capable of correcting high-order monochromatic aberrations of thehuman eye.

Unlike current contact lenses, customized contact lenses or contactlenses capable of correcting high order aberrations inevitably need tohave a complex surface design and/or a spatial distribution of index ofrefraction. The design, production and metrology-characterization ofsuch contact lenses with complex surfaces and spatial distribution ofindex of refraction can not be met by current lens designing,manufacturing and characterizing technologies.

U.S. Pat. No. 6,241,355 discloses a method of computer-aided contactlens design using spline-based mathematical surfaces withoutrestrictions of rotational symmetry. The patent teaches that each of theanterior surface, posterior surface and peripheral edge system of acontact lens can be described by one or a plurality of piecewisefunctions that satisfy a set of associated constraints of smoothness andthereby a contact lens can be produced to have a posterior surface thatprovides a good fit to a cornea having a complicated shape. However, thepatent does not disclose how to design and fabricate a contact lenscapable of correcting high-order aberrations, nor suggest that thedesign and fabrication of a contact lens capable of correctinghigh-order aberrations can be accomplished.

U.S. Pat. Nos. 5,777,719 and 6,095,651 disclose a concept that contactlenses for correcting at least third-order wavefront aberrations of theliving eye might be fabricated based on a final correction signal thatcontrol a deformable mirror to compensate for the aberrations of theliving eye. Although the patents teach that high-order aberrations ofthe human eye can be measured by using a Hartmann-Shack wavefront sensorand then corrected in a closed feedback loop with a deformable mirror asa compensating optical component, there are no methods or algorithmsdefined for converting the final correction signal, that controls areflective optics (i.e., a deformable mirror) to compensate for theaberrations, into a signal, that produces a refractive optics (i.e., acontact lens) capable of correcting the aberrations, nor examples whichshows that a contact lens can be fabricated to correct high-orderaberrations.

U.S. Pat. No. 6,086,204 discloses a method for correcting the opticalaberrations beyond defocus and astigmatism of an eye fitted with anoriginal contact lens having a known anterior surface shape by providinga modified or new contact lens which has its anterior surface reshapedfrom said original contact lens's anterior surface. The patent teachesthat a modified or new contact lens is produced by first measuring theoptical aberrations of an eye fitted with an original contact lens, thenperforming a mathematical analysis of the eye's optical aberrations whenfitted with the original contact lens to determine the modified anteriorsurface shape, and finally fabricating the modified anterior surface bymethods that remove, add or compress material or alter the surfacechemistry. There are some limitations in the method disclosed in U.S.Pat. No. 6,086,204. First, the posterior surface is not variable and ispredetermined by the original contact lens. Second, a first contactlens, that is unable to correct high-order aberrations, must befabricated, then be tried on by a patient, and finally be modified or anew contact lens having a posterior surface identical to that of theoriginal contact lens is fabricated. The method disclosed in U.S. Pat.No. 6,086,204 could have a long lens design cycle and concept evaluationtime.

WO-A-01/11418 discloses a system and method of integrating cornealtopographic data and ocular wavefront data with primary ametropiameasurements to create a soft contact lens design. WO-A-01/11418 teachesthat a better fitting soft contact lens can be designed by achieving acontact lens back surface which is uniquely matched to a particularcorneal topography, or which is an averaged shape based on theparticular corneal topography. However, WO-A-01/11418 does not disclosenor suggest how to design and fabricate a contact lens capable ofcorrecting high-order aberrations.

There still remains a need for a system and method for designing and/orfabricating contact lenses capable of correcting high-order aberrationsof an eye. There is also a need for a system and method forcharacterizing the metrology of a contact lens capable of correctinghigh-order aberrations of an eye.

SUMMARY OF THE INVENTION

It is a primary objective of the present invention to provide a systemand method for designing a customized ophthalmic lens.

It is also an objective of the present invention to provide a system andmethod for producing a customized ophthalmic lens.

It is a further objective of the present invention to provide a systemand method for manufacturing customized ophthalmic lenses.

It is still a further objective of the present invention to provide asystem and method for characterizing the metrology of a customizedophthalmic lens or an ophthalmic lens capable of correcting high orderaberrations.

These and other objectives are achieved by the various aspects of theinvention described herein.

The invention, in one aspect, provides a method for creating acomputational model eye which reproduces aberrations of an eye of anindividual and can find particular use in the design and production of acustomized ophthalmic lens or an ophthalmic lens capable of correctinghigh-order aberrations. The computational model eye comprises: at leastone refractive optical element having a first surface with a topographyidentical to the corneal topography and a second surface and a modelretina having a model fovea having a lattice of pixels. The aberrationsof an eye are reproduced by the optical element alone or in combinationwith at least one additional optical element. The method for creating acomputational model eye comprises the steps of: (1) providing a set ofcharacteristic data of an eye of an individual, wherein said set ofcharacteristic data comprise wavefront aberrations of the eye andcorneal topography data; (2) converting the corneal topography data intoa mathematical description representing a first surface of a firstrefractive optical element, the first optical refractive element havingthe first surface and an opposite second surface; (3) designing andoptimizing the second surface of the first refractive optical element sothat the first refractive optical element, alone or in combination witha second refractive optical element that has a third surface and anopposite fourth surface and an index of refraction distribution,reproduces the wavefront aberrations of the eye; (4) designing a modelretina that has a curvature of the human retina and comprises a modelfovea having a lattice of pixels representing photoreceptors; and (5)arranging the first refractive optical element and the model retinaalong an optical axis in a way such that the distance between the foveaand the center of the first surface of the first refractive opticalelement is equal to the visual axial length of the human eye.Preferably, the computational model eye comprises a model crystallinelens as the second refractive optical element and a model cornea as thefirst refractive optical element, wherein the model crystalline lens isconstructed on the basis of the crystalline lens of the human eye. Inthis preferred embodiment, the model cornea, the model crystalline lensand the model retina are arranged in a way identical to theircorresponding elements in the human eye. More preferably, thecomputational model eye further comprises a pupil with a pupil sizeranging from 2.0–8.0 mm, adjustable according to the individual's ageand/or illumination light intensity.

The invention, in another aspect, provides an iterative process foroptimizing an optical design of an ophthalmic lens. The iterativeprocess comprising the steps of: (1) determining visual performanceinformation of the optical design of an ophthalmic lens with acomputational model eye that reproduces aberrations of an eye of anindividual, wherein the computational model eye comprises alens-supporting surface having corneal topography of the eye and a modelretinal having a curvature of the human retina and a model foveacomprising a lattice of pixels that represent photoreceptors, whereinthe distance between the model fovea and the center of thelens-supporting surface is equal to visual axial length of the humaneye; (2) modifying the optical design of the ophthalmic lens on thebasis of the visual performance information determined in step (1); and(3) repeating steps (1) and (2) until visual performance of a modifiedoptical design of the ophthalmic lens is optimized.

The invention, in another aspect, provides a method and system fordesigning a customized ophthalmic lens or an ophthalmic lens which iscapable of correcting high order aberrations. The lens-designing methodcomprises the steps of: (1) providing a set of characteristic data of aneye of an individual, wherein said set of characteristic data compriseswavefront aberrations of the eye and corneal topography; (2) creating acomputational model eye that reproduces the wavefront aberrations of theeye, wherein the computational model eye comprise a lens-supportingsurface having the corneal topography of the eye and a model retinalhaving a model fovea comprising a lattice of pixels that representphotoreceptors, wherein the distance between the model fovea and thecenter of the lens-supporting surface is equal to visual axial length ofthe human eye; (3) designing an optical model lens which is capable ofcompensating for the wavefront aberrations of the eye; (4) evaluatingthe visual performance of said optical model lens with the computationalmodel eye; (5) obtaining visual performance information of said opticalmodel lens; (6) modifying the design of said optical model lens on thebasis of said visual performance information to improve corrections ofthe aberrations of the eye if the visual performance of said opticalmodel lens is not optimal; (7) repeating steps (4) to (6) until thevisual performance of said optical model lens is optimal; and (8)transforming the optimized optical model lens into a set of mechanicalparameters for making said customized ophthalmic lens or said ophthalmiclens capable of correcting high order aberrations. The lens-designingsystem includes a computer system comprising: (a) a model eye designmodule for creating a computational model eye that reproducesaberrations of an eye of an individual, wherein the computational modeleye comprises a lens-supporting surface having corneal topography of theeye and a model retina having a curvature of the human retina and amodel fovea comprising a lattice of pixels that representphotoreceptors, wherein the distance between the model fovea and thecenter of the lens-supporting surface is equal to visual axial length ofthe human eye; (b) an optical design module for designing an opticalmodel lens to compensate for the wavefront aberrations of the eye and toaccommodate the corneal topography of the eye of the individual or anaveraged corneal topography derived from population studies, (c) alens-designing optimization module for performing an iterativeoptimization process comprising (1) determining visual performanceinformation of the optical model lens with the computational model eye,(2) modifying the design of the optical model lens on the basis of saidvisual performance information to improve corrections of the aberrationsof the eye if the visual performance of said optical model lens is notoptimal, and repeating steps (1) and (2), if necessary, until visualperformance of a modified design of the optical model lens is optimized;and (d) a mechanical design module for generating a CAD output filecontaining parameters for making said customized ophthalmic lens or saidophthalmic lens capable of correcting high order aberrations, based onthe optimized optical model lens. Preferably, the system furthercomprises a sensor system, which is capable of determining the set ofcharacteristics data of the eye.

The invention, in still another aspect, provides a method and system forproducing a customized ophthalmic lens or an ophthalmic lens which iscapable of correcting high order aberrations. The lens-producing methodcomprises the eight steps of the above lens-designing method and furthercomprises the following steps: (9) converting the set of mechanicalparameters for making the lens into control signals that control acomputer-controllable manufacturing device and (10) producing the lensusing the computer controllable manufacturing device. The lens-producingsystem includes a computer-controllable manufacturing device and acomputer system comprising: (a) a model eye design module for creating acomputational model eye a model eye design module for creating acomputational model eye that reproduces aberrations of an eye of anindividual, wherein the computational model eye comprises alens-supporting surface having a corneal topography of the eye and amodel retina having a curvature of the human retina and a model foveacomprising a lattice of pixels that represent photoreceptors, whereinthe distance between the model fovea and the center of thelens-supporting surface is equal to a visual axial length of the humaneye; (b) an optical design module for designing an optical model lens tocompensate for the wavefront aberrations of the eye of the individualand to accommodate the corneal topography of the eye of the individual,(c) a lens-designing optimization module for performing an iterativeoptimization process comprising (1) determining visual performanceinformation of the optical model lens with the computational model eye,(2) modifying the design of the optical model lens on the basis of saidvisual performance information to improve corrections of the aberrationsof the eye if the visual performance of said optical model lens is notoptimal, and repeating steps (1) and (2), if necessary, until visualperformance of a modified design of the optical model lens is optimized;(d) a mechanical design module for generating a CAD output filecontaining parameters for making the ophthalmic lens, based on theoptimized optical model lens; (e) a signal module for converting saidCAD output file into control signals that control thecomputer-controllable manufacturing device to produce said ophthalmiclens; and (f) a manufacturing control module for controlling thecomputer-controllable manufacturing device to produce said ophthalmiclens. Preferably, the system further comprises a sensor system, which iscapable of determining the set of characteristic data of the eye.

The invention, in a further aspect, provides a system and method forcharacterizing the optical metrology of an ophthalmic lens capable ofcorrecting higher order aberrations of an eye. The metrologycharacterizing system comprises: (a) a monochromatic point light source;(b) a diffraction limited model eye in front of said monochromatic pointlight source, wherein said model eye has a posterior surface and anopposite anterior surface having an averaged corneal topography of apopulation; (c) a lubricating system to simulate a tear film on theanterior surface of the model eye; (d) an aperture which simulates thehuman fovea and is located between said light source and said model eye,wherein said simulated fovea is capable of moving along the light pathvia manual means or via a precision motion control system to nulldefocus; and (e) a wavefront sensor in front of said model eye.Preferably, the metrology system further comprises an additionalaperture to simulate the pupil or iris of the eye, wherein theadditional aperture is located along the optical pathway between thewavefront sensor and the refractive optics. The optical metrologycharacterizing method comprises (1) installing said contact lens in theabove metrology system and (2) characterizing the metrology of saidcontact lens.

The invention, in another further aspect, provides a method formanufacturing ophthalmic lenses capable of correcting aberrations ofeyes. The lens-manufacturing method of the invention comprises the stepsof: (1) analyzing eyes of each of the individuals from a population toobtain a set of characteristic data comprising aberrations and cornealtopography; (2) compiling population statistics of aberrations andcorneal topographies; (3) creating a plurality of computational modeleyes, each of which generates averaged aberrations representingstatistically one of a plurality of nominal segments of the population,wherein each of plurality of computational model eyes comprises alens-supporting surface having an averaged corneal topography for one ofa plurality of nominal segments of the population and a model retinahaving a model fovea comprising a lattice of pixels that representphotoreceptors, wherein the distance between the model fovea and thecenter of the lens-supporting surface is equal to a visual axial lengthof the human eye; (4) designing a plurality of optical model lenses eachof which accommodates the averaged corneal topography of the eyes of oneof the plurality of nominal segments of the population and corrects theaveraged aberrations of the eyes of one of the plurality of nominalsegments of the population; (5) optimizing optical designs of theplurality of the optical model lenses with one of the plurality of thecomputational model eyes; (6) transforming the plurality of theoptimized optical model lenses into a plurality of sets of mechanicalparameters each for making one contact lens; (7) creating one stockkeeping unit (SKU) for each of each of the contact lenses; and (8)manufacturing said ophthalmic lenses having a specific SKU.

The invention, in still a further aspect, provides a method for orderinga pair of customized contact lenses, the method comprising the steps of:(1) providing wavefront aberrations and corneal topographies of thefirst and second eyes of a patient to a client computer system; (2)sending a first request, under control of the client computer system, tolook for a pair of customized contact lenses capable of correcting theaberrations of both eyes, to a server system; (3) receiving the firstrequest by the server system; (4) converting the wavefront aberrationsand corneal topographies into a querying order in a format readable by aquery engine in the server system; (5) using the querying order tosearch against a SKU database to obtain a first and a second list ofSKUs, wherein each of the SKUs in the first list is capable ofaccommodating adequately the corneal topography of the first eye and ofcorrecting adequately the wavefront aberrations of the first eye,wherein each of the SKUs in the second list is capable of accommodatingadequately the corneal topography of the second eye and of correctingadequately the wavefront aberrations of the second eye; (6) displayinglens information related to each of the two list of SKUs with SKUidentifiers under control of the client computer system; (7) selecting apair of SKUs with a first SKU identifier and a second SKU identifierunder control of the client computer system or a choice to make a newpair of customized contact lenses; (8) sending a second request to ordera pair of contact lenses with the first and the second SKU identifier orto order the new pair of customized contact lenses to be made, alongwith a customer identifier that identifies the patient and/or aneye-care practitioner who takes care of the patient, under control ofthe client computer system; (9) receiving the second request by theserver system; (10) retrieving additional information previously storedfor the patient and/or the eye-care practitioner identified by thecustomer identifier in the received second request; and (11) generatingan order to deliver the pair of customized lenses for the patient or theeye-care practitioner identified by the customer identifier in thereceived second request using the retrieved additional information.

The invention, in still another further aspect, provides a clientcomputer system for ordering pairs of customized contact lenses and aserver system for generating order for pairs of customized contactlenses.

These and other aspects of the invention will become apparent from thefollowing description of the preferred embodiments taken in conjunctionwith the following drawings. As would be obvious to one skilled in theart, many variations and modifications of the invention may be effectedwithout departing from the spirit and scope of the novel concepts of thedisclosure.

BRIEF DESCRPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a system for designing andproducing an ophthalmic lens capable of correcting high orderaberrations according to a preferred embodiment of the presentinvention.

FIG. 2 schematically depicts a process for designing and producing anophthalmic lens capable of correcting high order aberrations accordingto a preferred embodiment of the present invention.

FIG. 3 schematically shows a reduced computational model eye accordingto a preferred embodiment of the invention.

FIG. 4 schematically shows an anatomical computational model eyeaccording to a preferred embodiment of the invention.

FIG. 5 schematically shows a metrology system according to a preferredembodiment of the invention.

FIGS. 6A to 6C show a flow diagram depicting a process for designing andmanufacturing ophthalmic lenses capable of correcting high orderaberrations according to a preferred embodiment of the presentinvention.

FIG. 7 is block diagram schematically depicting a system and method forplacing an order for purchasing a pair of customized ophthalmic lensesaccording to a preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the invention is a method for creating areduced computational model eye, the method comprising: (1) providing aset of characteristic data of an eye of an individual, wherein said setof characteristic data comprise wavefront aberrations and cornealtopography data of the eye of an individual; (2) converting the cornealtopography data into a mathematical description representing theanterior surface of a model lens; (3) designing and optimizing theposterior surface of the model lens so that the model lens reproducesthe wavefront aberrations of the eye of the individual; (4) designing amodel retina that has a curvature of the human retina and comprises amodel fovea having a lattice of pixels representing photoreceptors, and(4) arranging the model lens and the model retina along an optical axisin a way such that the distance between the model fovea and the vertexof the anterior surface of the model lens is equal to visual axiallength of the human eye.

“A computational model eye” as used herein refers to an interactivecomputer optical model that represents the optical characteristics of aneye of an individual, preferably in a relaxed state.

“A reduced computational model eye” as used herein refers to aninteractive computer optical model that comprises: (1) a model lenshaving a posterior surface and an anterior surface having the cornealtopography of an eye of an individual, wherein the model lens is capableof duplicating aberrations of that eye; and (2) a model retina that hasa curvature of the human retina and a model fovea comprising a hexagonallattice of pixels, preferably 2.5 micron pixels, representingphotoreceptors, wherein the retina is placed along an optical axis suchthat the distance between the model fovea and the center of the anteriorsurface of the model lens is identical to the visual axial length of thehuman eye. Preferably, a reduced computational model eye furthercomprises a model pupil located between the model lens and the modelretina. The size of the model pupil is about from 2.0 mm to 8.0 mm andadjustable according to the individual's age and/or illumination lightintensity. Preferably, the size of the model fovea is about 2 mm.

“The posterior surface of the model lens” refers to the surface of themodel lens which is facing toward the retina in a reduced computationalmodel eye. “The anterior surface of a model lens” refers to the surfaceon which a contact lens can be placed.

“An optical axis” refers to a line of best fit through the centers ofcurvatures of surfaces of all refractive optical elements and the modelfovea in a computation model eye. The optical axis of the human eyerefers to the line of best fit through centers of curvatures of therefracting surfaces.

“The human eye” means an eye that represents statistically all normaleyes of a given population. The human eye comprises the human cornea,the human crystalline lens, and the human retina. “The human retina”means a retina that represents statistically retinas of all normal eyesof a given population. “The human cornea” refers to a cornea thatrepresents statistically corneas of all normal eyes of a givenpopulation.

The term “visual axial length” refers to the distance between theophthalmometric pole and the fovea along the visual axis of the relaxedeye. The ophthalmometric pole refers to the intercept of the visual axisat the anterior surface of the cornea of the relaxed eye. The visualaxis of the human eye refers to the line joining a fixation point andthe foveal image by way of the nodal points.

FIG. 3 schematically shows a reduced computational model eye accordingto a preferred embodiment of the invention. A model lens 320 has aposterior surface 322 and an opposite anterior surface 321. A contactlens 14 having a posterior (concave) surface (or base curve) 17 and ananterior (convex) surface (or front curve) 11 is placed on the anteriorsurface 321 of the model lens 320. The optical axis 350 of the modellens 320 passes through the center of a model fovea 340 in a modelretina 330 which has a curvature of the human retina. The model fovea340 has a size of about 2.0–8.0 mm and comprises a hexagonal lattice of2.5 micron pixels (not shown). The distance between the model fovea 340and vertex of the anterior surface 321 is identical to the visual axiallength of the eye of an individual.

Another preferred embodiment is a method for creating an anatomicalcomputational model eye, the method comprising: (1) providing a set ofcharacteristic data of an eye of an individual, wherein said set ofcharacteristic data comprise wavefront aberrations and cornealtopography data of the eye of the individual; (2) creating a modelcrystalline lens having a refractive power range equal to that of thenatural crystalline lens of the human eye; (3) converting the cornealtopography data into a mathematical description representing theanterior surface of a model cornea; (4) designing and optimizing theposterior surface of the model cornea so that the combination of themodel cornea and the model lens reproduces the wavefront aberrations ofthe eye of the individual; (5) designing a model retina that has acurvature of the human retina and comprises a model fovea having ahexagonal lattice of pixels representing photoreceptors; and (5)arranging the model cornea, the model crystalline lens and the modelretina along an optical axis in a way such that the distance between thefovea and the vertex of the anterior surface of the model cornea isequal to visual axial length of the human eye. In a preferredembodiment, the size of pixels is about 2.5 micron and the size of themodel fovea is 2 mm in diameter.

“An anatomical computational model eye” as used herein refers to aninteractive computer optical model that is capable of duplicatingaberrations of an eye of an individual and comprises at least thefollowing three optical elements: a model cornea having the cornealtopography of the eye of the individual, a model crystalline lens whichpreferably represents a natural crystalline lens typically for an agegroup of a population, and a model retina having a fovea that has acurvature of the human retina and a model fovea comprising a hexagonallattice of pixels, preferably 2.5 micron pixels, representingphotoreceptors. All the optical elements are arranged along an opticalaxis in a way identical to their arrangement in the human eye, whereinthe distance between the fovea and the vertex of the model cornea isequal to visual axial length of the human eye. The arrangement of theoptical elements in an anatomical computational model eye refers totheir position relative to each other along the optical axis. Forexample, the position of the crystalline lens relative to the retina isdefined by an optical axial distance between the posterior surface ofthe crystalline lens and the fovea. The value of the optical axialdistance between the posterior surface of the crystalline lens and thefovea is well known and can be found in literatures and books.Preferably, an anatomical computational model eye further comprises apupil located between the model cornea and the model crystalline lens.The size of the model pupil is about from 2.0 mm to 8.0 mm andadjustable according to the individual's age and/or illumination lightintensity. More preferably, an anatomical computational model eyefurther comprises other refractive elements in the eye, such as fluidsin the anterior and posterior chambers.

An anatomical computational model eye of the invention is ananatomically correct representation of the eye and has additionaldegrees of freedom which allow for a more complete description ofdynamic imaging for modeling presbyopia.

“The posterior surface of the model cornea” refers to the surface thathas a concave curvature and that is facing toward the model crystallinelens. “The anterior surface of a model lens” refers to the surfacehaving a convex curvature, on which a contact lens can be placed.

FIG. 4 schematically shows an anatomical computational model eyeaccording to a preferred embodiment of the invention. A model cornea 410has a posterior surface 412 and an opposite anterior surface 411. Acontact lens 14 having a posterior (concave) surface (or base curve) 17and an anterior (convex) surface (or front curve) 11 is placed on theanterior surface 411 of the model cornea 410. An optical axis 450 is theline of best fit through the centers of curvatures of all surfaces ofthe model cornea 410, a model crystalline lens 420 and a model fovea 340in a model retina 330. The model retina 330 has a curvature of the humanretina. The model crystalline lens 420 has a first convex surface 421,an opposite second convex surface 422 and a midplane. The model fovea340 has a size of 2 mm in diameter and comprises a hexagonal lattice of2.5 micron pixels (not shown). The distance between the model fovea 340and vertex of the anterior surface 411 of the model cornea 410 isidentical to the visual axial length of the eye of an individual. Theoptical axial distance from the model fovea to the posterior surface ofthe model crystalline lens is 7.68 mm.

The wavefront aberrations of an eye of an individual can be determinedby any suitable methods known to one skilled in the art. For example,Liang et al. in J. Optical Soc. Am. 11:1–9, the entirety of which areherein incorporated by reference, teach how to determine wavefrontaberrations of an eye at various pupil diameters using a Hartmann-Shacksystem. The wavefront aberrations generally are quantified in Zernikepolynomials which are a set of functions that are orthogonal over theunit circle. Since Zernike polynomials are orthogonal, the aberrationsare separable and can be treated as such. The first order Zernike modesare the linear terms. The second order Zernike modes are the quadraticterms, which correspond to the aberrations such as defocus andastigmatism. The third order Zernike modes are the cubic terms, whichcorrespond to the coma and coma-like aberrations. The fourth orderZernike modes contain spherical aberrations as well as other modes. Thefifth Zernike modes are the higher-order, irregular aberrations. Localirregularities in the wavefront within the pupil are represented bythese higher-order Zernike modes. “High-order” aberrations of an eye asused herein refers to monochromatic aberrations beyond defocus andastigmatism, namely, third order, fourth order, fifth order, and higherorder wavefront aberrations.

Corneal topographic data can be acquired using a corneal topographer orvideokeratoscope. Corneal topography data may be in any forms suitablefor use in designing an ophthalmic lens. Exemplary forms include, butare not limited to, Zernike polynomials, point cloud data and the like.Preferably, corneal topography data are in a form in which the wavefrontaberrations of an eye are quantified. The corneal topography datacontained in the set of characteristic data of an eye can also be anaveraged corneal topography derived from population studies. Suchaveraged corneal topography data may optionally be incorporated as aparameter in algorithms for creating a computational model eye.

Visual axial length of the human eye refers to a visual axial lengththat represents statistically the visual axial length of eyes of a givenpopulation. The value of the visual axial length of the human eye can befound in the literatures and books and may be incorporated as aparameter in the algorithms for creating a computational model eye.Preferably, the visual axial length is the actually measured visualaxial length of an eye of an individual.

The set of characteristic data of an eye of an individual can also be aset of known characteristic data that represent statistically a nominalsegment of population on the basis of population studies. Such set ofcharacteristic data of the eye can be used in the designing andmanufacturing of customized ophthalmic lenses. Furthermore, a pluralityof such set of characteristic data of the eye can be used in creatingand producing stock keeping units (SKUs) of customized ophthalmiclenses.

“A customized ophthalmic lens”, as used herein, means: (1) an ophthalmiclens that has one of the surfaces accommodating the corneal topographyof an eye of an individual and/or can correct high order aberrations ofthe eye or that has an asymmetrical surface design and/or can correcthigh order aberrations of the eye; (2) an ophthalmic lens that isdesigned using input of aberration measurements of an eye of anindividual; or (3) an ophthalmic lens with bifocal, multi-focal orprogressive multifocal properties, that is designed using input ofaberration measurements of an eye of an individual.

In a more preferred embodiment, the set of characteristic data furthercomprises corneal pachymetry data. Such additional data are useful forbuilding an anatomical computational model eye. The posterior surface ofthe model cornea can be generated on the basis of the anterior surfacetopography and the corneal pachymetry data. Such anatomicalcomputational model eye can find particular use in designing andproducing customized intraocular lenses, as described below.

U.S. Pat. No. 5,963,300, herein incorporated by reference in itsentirety, discloses a single system and methods for measuring wavefrontaberrations, corneal topographic data, corneal pachymetry, pupil size,retinal acuity, ocular acuity, etc.

There are many kinds of mathematical functions that can be used todescribe the corneal topography of an eye. Exemplary mathematicalfunctions include conic and quadric, polynomials of any degree, Zernikepolynomials, exponential functions, trigonometric functions, hyperbolicfunctions, rational functions, Fourier series, and wavelets. Preferably,a combination of two or more mathematical functions are used to describethe corneal topography of an eye. More preferably, Zernike polynomialsare used to describe the corneal topography of an eye. Even morepreferably, Zernike polynomials and spline-based mathematical functionsare used together to describe the corneal topography of an eye. Anindividual skilled in the art will know how to convert the cornealtopography data of an eye into a mathematical description (one or moremathematical functions) representing the corneal topography of an eye.Such mathematical description can be used as the anterior surface of amodel lens in a reduced computational eye model or as the anteriorsurface of a model cornea in an anatomical computational eye model.

The posterior surface of a model lens in a reduced computational modeleye in a form of mathematical description can be designed, for example,by subtracting the optical aberrations derived from the cornealtopography from the wavefront aberrations of an eye, or by ray tracingof the anterior surface of the model lens. The ray tracing technique iswell known in the art. Several commercially-available optical designsoftware packages contain ray tracing programs. Exemplary optical designsoftware packages include Zemax from Focus Software, Inc. and AdvancedSystem Analysis program (ASAP) from Breault Research Organization.

Preferably, a mathematical description for the posterior surface of themodel lens in a reduced computational model eye is polynomials, thecoefficients of which can be optimized in an optimization routine suchas a least square fit or equivalent to generate the optimized posteriorsurface which allow the model lens to reproduce the wavefrontaberrations of the eye. More preferably, a set of aberrationcoefficients, that represent the wavefront aberrations of an eye, areused as weighted operands in an optical design optimization loop tooptimize the posterior surface of the model lens so that the reducedcomputational model eye can reproduce the wavefront aberrations of theeye.

The posterior surface of a model cornea in an anatomical computationalmodel eye can be designed, for example, by subtracting the opticalaberrations derived from both the corneal topography (the anteriorsurface of the model cornea) and a model crystalline lens from theaberrations of the eye, or by ray tracing of the anterior surface of themodel cornea. Preferably, a mathematical description is polynomials, thecoefficients of which can be optimized in an optimization routine suchas a least square fit or equivalent to generate the optimized posteriorsurface which allow the anatomical computation model eye to reproducethe wavefront aberrations of the eye. More preferably, a set ofaberration coefficients, that represent the wavefront aberrations of aneye, are used as weighted operands in an optical design optimizationloop to optimize the posterior surface of the model cornea so that theanatomical computational model eye can reproduce the wavefrontaberrations of the eye.

The refractive power range of the model crystalline lens in ananatomical computational model eye generally can be generated based onany combinations of the surface topographies and the index of refractiondistribution. For example, the topographies and the index of refractiondistribution of a natural crystalline lens in the eye representing anage group of a population can be used directly to generate the modelcrystalline lens in an anatomical computational model eye. Data, such asthe topographies of the two surfaces, index of refraction distributionand the refractive power range of the crystalline lens of the human eye,can be found from literatures and reference books, for example, Opticsof the Human Eye, (Atchison and Smith, eds.), Butterworth-Heinemann:Boston 2000 and Liou et al., J. Opt. Soc. Am. 14: 1684–1695.Alternatively, based on a single index of refraction, the topographiesof the two surfaces of the model crystalline lens can be varied andoptimized to obtain a desired refractive power range corresponding tothat of the natural crystalline lens in the human eye.

In a preferred embodiment, presbyopia information is also preferablyincorporated in creating the refractive power range of the modelcrystalline lens in an anatomical computational model eye. It isbelieved that as an individual ages the natural crystalline lenses ofthe eyes tend to harden, thicken and the surfaces become steeper. Thehardening makes it difficult for the eye crystalline lens to change itssurface curvature (i.e. bending). This inability of the eye crystallinelens to bend is a condition referred to as presbyopia.

In a preferred embodiment, the age of an individual is taken intoaccount for creating a model pupil in a computational model eye,particularly for adjusting the pupil size. The manner in which the sizeof an individual's pupil varies is predictable, principally depending onthe illumination level and the age of the individual. For people of thesame age, the size of their pupils at maximum and minimum dilationchanges as a function of illumination level, in the same orsubstantially the same way. Thus, the size of an individual's pupils atminimum and maximum dilation can be estimated based upon the age of thatindividual. A pupil with appropriate size will be particularly usefulfor evaluating the design of a lens for correcting presbyopia.

In the algorithm used for building a computational model eye, thechromatic dispersion and Stiles-Crawford effects are preferablyincorporated.

The computational model eye of the present invention can find use inevaluating the visual performance of the optical design of an ophthalmiclens by determining merit functions such as point spread function (PSF),line spread function (LSF), modulation transfer function (MTF), phasetransfer function, contrast threshold function, contrast sensitivityfunction (CSF) and other merit functions known or constructed by thoseskilled in the art. A computational model eye of the invention can alsoused in performing bitmap image analysis, ghost image analysis, andfocal length and optical power analysis, because the computational modeleye contains a model retina having a model fovea having a hexagonallattice of pixels that represent photoreceptors. The bitmap imageanalysis and ghost image analysis are very useful information foroptimizing bifocal/multifocal lens design. Visual performanceinformation of an optical design of an ophthalmic lens is useful foroptimizing the optical design of that lens.

For evaluating the visual performance of the optical design of a contactlens, the contact lens is placed on the anterior surface of the firstrefractive optical element in a computational model eye.

When evaluating the visual performance of the optical design of anaphakic intraocular lens, the model crystalline lens is first deletedfrom an anatomical computational model eye and then the aphakicintraocular lens is placed in a position between the model cornea andthe model crystalline lens. When evaluating the visual performance ofthe optical design of a phakic intraocular lens, the phakic intraocularlens is placed between the model cornea and the model crystalline lens.Preferably, the anatomical computational model eye comprises a modelcornea which is created based on the corneal topography and pachymetrydata of an eye.

The computational model eye of the present invention may find use inestimating the visual acuity of the optical design of an ophthalmic lensby determining merit functions such as point spread function (PSF), linespread function (LSF), modulation transfer function (MTF), phasetransfer function, contrast threshold function, contrast sensitivityfunction (CSF) and other merit functions known or constructed by thoseskilled in the art, and by performing bitmap image analysis, ghost imageanalysis, and focal length and optical power analysis.

Another preferred embodiment of the invention is an iterative processfor optimizing an optical design of an ophthalmic lens, the iterativeprocess comprising the steps of: (1) determining visual performanceinformation of the optical design of an ophthalmic lens with acomputational model eye that reproduces aberrations of an eye of anindividual, wherein the computational model eye comprises alens-supporting surface having the corneal topography of the eye and amodel retina having a model fovea comprising a hexagonal lattice ofpixels that represent photoreceptors, wherein the distance between themodel fovea and the center of the lens-supporting surface is equal to avisual axial length of the human eye; (2) modifying the optical designof the ophthalmic lens on the basis of the visual performanceinformation determined in step (1); and (3) repeating steps (1) and (2)until visual performance of a modified optical design of the ophthalmiclens is optimized. Preferably, the visual performance informationcomprises at least a merit function selected from the group consistingof point spread function (PSF), modulation transfer function (MTF),bitmap image analysis, ghost image analysis, focal length analysis andoptical power analysis.

Another preferred embodiment of the invention is a method for designinga customized ophthalmic lens, comprising the steps of: (1) providing aset of characteristic data of an eye of an individual, wherein said setof characteristic data comprise wavefront aberrations and cornealtopography of the eye of the individual; (2) creating a computationalmodel eye capable of duplicating the wavefront aberrations of the eye ofthe individual, wherein the computational model eye comprises alens-supporting surface having the corneal topography of the eye of theindividual and a model retina having a model fovea comprising a latticeof pixels that represent photoreceptors, wherein the distance betweenthe model fovea and the vertex of the lens-supporting surface is equalto the visual axial length; (3) designing an optical model lens which iscapable of compensating for the wavefront aberrations of the eye of theindividual; (4) evaluating the visual performance of said optical modellens with the computational model eye; (5) obtaining visual performanceinformation of said optical model lens; (6) modifying the design of saidoptical model lens on the basis of said visual performance informationto improve corrections of the aberrations of the eye, if the visualperformance of said optical model lens is not optimal; (7) repeatingsteps (3) to (6), if necessary, until the visual performance of saidoptical model lens is optimal; and (8) transforming the optical modellens having optimal visual performance into a set of mechanicalparameters for making said customized ophthalmic lens.

“A lens-supporting surface” as used herein refers to the anteriorsurface of a model lens in a reduced computational model eye or theanterior surface of a model cornea in an anatomical computational modeleye.

“An optical model lens” refers to an ophthalmic lens that is designed ina computer system and generally does not contain other non-opticalsystems which are parts of an ophthalmic lens. Exemplary non-opticalsystems of a contact lens include, but are not limited to bevel,lenticular, and edge that joins the anterior and posterior surfaces of acontact lens.

“A bevel” refers to a non-optical surface zone located at the edge ofthe posterior surface of a contact lens. Generally, the bevel is asignificantly flatter curve and is usually blended with the base curve(optical posterior surface) of a contact lens and appears as an upwardtaper near the edge. This keeps the steeper base curve radius fromgripping the eye and allows the edge to lift slightly. This edge lift isimportant for the proper flow of tears across the cornea and makes thelens fit more comfortable.

“A lenticular” refers to a non-optical surface zone of the anteriorsurface of a contact lens between the optical zone and the edge. Theprimary function of the lenticular is to control the thickness of thelens edge.

It is well known to those skilled in the art that the optical power of acontact lens is, inter alia, a function of the index of refraction ofthe lens material and the algebraic difference between the curvatures ofthe anterior surface and the posterior surface of the lens. Generallywhen designing a customized contact lens or a contact lens capable ofcorrecting high-order aberrations of an eye, the posterior surface ofthe lens is first designed to accommodate the corneal topography of thateye or a corneal topography statistically representing a segment of apopulation. A posterior surface with such design will provide a good oradequate fit to the cornea of an eye and therefore enhance the wearer'scomfort. The anterior surface of the lens then is designed and optimizedso that the designed lens compensates for the aberrations of that eye.

It is believed that the posterior surface of a contact lens does notneed to match perfectly the corneal topography of an eye. A perfectmatch means the posterior surface of a contact lens is exactlysuperimposable on a corneal topography. A contact lens, which has aposterior surface perfectly matching the corneal topography of an eye,may have inadequate on-eye movement of the lens and may have an adverseimpact on wearer's comfort.

When designing a contact lens capable of correcting presbyopia of anindividual, it is preferable to incorporate the following optical designparameters including, but not limited to, pupil diameter range,alternating/simultaneous function, monocular/binocular function, segmentdesign (such as shape and number of zones, discrete/progressive zones,lens added power, etc.), and ages and occupational factors of thatindividual.

When designing a contact lens for a keratoconus patient, the base curve(concave surface) of that contact lens is preferably designed toaccommodate the corneal topography of that patient.

When designing a contact lens for correcting astigmatism, one needs totake into account lens orientation and method of orientation to be used.

It is well known in the art that when a soft contact lens is placed onthe eye, it conforms to the underlying shape of cornea. The extent ofsoft lens flexure (wrap) depends on the modulus of elasticity of lensmaterials. Preferably, soft lens flexure needs to be taken into accountin the designing of an optical lens and in the evaluating of its visualperformance with a computational model eye.

Any mathematical function can be used to describe the anterior surface,posterior surface, peripheral edge of an ophthalmic lens, as long asthey have sufficient dynamic range which allow the design of that lensto be optimized. Exemplary mathematical functions include conic andquadric functions, polynomials of any degree, Zernike polynomials,exponential functions, trigonometric functions, hyperbolic functions,rational functions, Fourier series, and wavelets. Preferably, acombination of two or more mathematical functions are used to describethe front (anterior) surface and base (posterior) surface of anophthalmic lens. More preferably, Zernike polynomials are used todescribe the front (anterior) surface and base (posterior) surface of anophthalmic lens. Even more preferably, Zernike polynomials andspline-based mathematical functions are used together to describe thefront (anterior) surface and base (posterior) surface of an ophthalmiclens.

Surface topographies, index of refraction distribution, diffractive orholographic structures of a designed optical and/or mechanical modellens can be optimized according to feedback from the evaluation of itsvisual performance with a computational model eye. Any known, suitableoptimization algorithms, for example, a least square fit or equivalent,can be used in the design optimization. Preferably, a set of aberrationcoefficients, that represent the wavefront aberrations of an eye, areused as weighted operands in an optical design optimization loop in theoptimization of the optical design of the ophthalmic lens. Morepreferably, artificial intelligence (AI) programs or neural networks areused in the optimization of the optical design of the ophthalmic lens.

Any known, suitable optical computer aided design (CAD) system may beused to design an optical model lens. Exemplary optical computer aideddesign systems includes, but are not limited to Advanced System Analysisprogram (ASAP) from Breault Research Organization and ZEMAX (FocusSoftware, Inc.). Preferably, the optical design will be performed usingAdvanced System Analysis program (ASAP) from Breault ResearchOrganization with input from ZEMAX (Focus Software, Inc.). ASAP willalso preferably be used in analysis of visual performance of opticalmodel lens.

The design of the optimized optical model lens can be transformed by,for example, a mechanical computer aided design (CAD) system, into a setof mechanical parameters for making a physical lens. Any known, suitablemechanical CAD system can be used in the invention. Preferably, thedesign of an optical model lens may be translated back and forth betweenthe optical CAD and mechanical CAD systems using a translation formatwhich allows a receiving system, either optical CAD or mechanical CAD,to construct NURBs or Beizier surfaces of an intended design. Exemplarytranslation formats include, but are not limited to, VDA (Verband derAutomobilindustrie) and IGES (Initial Graphics Exchange Specification).By using such translation formats, overall surface of lenses can be in acontinuous form that facilitates the production of lenses havingradially asymmetrical shapes. Beizier and NURBs surfaces are particularadvantageous for presbyopic design because multiple zones can beblended, analyzed and optimized. More preferably, the mechanical CADsystem is capable of representing precisely and mathematically highorder surfaces. An example of such mechanical CAD system isPro/Engineer.

When transforming the design of an optimized optical model lens into aset of mechanical parameters, parameters for some common features of afamily of ophthalmic lenses can be incorporated in the lens designingprocess. Examples of such parameters include shrinkage, non-optical edgezone and its curvature, center thickness, range of optical power, andthe like.

Another preferred embodiment of the invention is a system for designinga customized ophthalmic lens, the system comprising a computer systemincluding: (a) a model eye design module for creating a computationalmodel eye that reproduces aberrations of an eye of an individual,wherein the computational model eye comprises a lens-supporting surfacehaving the corneal topography of the eye and a model retina having acurvature of the human retina and a model fovea comprising a hexagonallattice of pixels that represent photoreceptors, wherein the distancebetween the model fovea and the center of the lens-supporting surface isequal to the visual axial length of the human eye; (b) an optical designmodule for designing an optical model lens to compensate for thewavefront aberrations of the eye of the individual and to accommodatethe corneal topography; (c) a lens-designing optimization module forperforming an iterative optimization process comprising (1) determiningvisual performance information of the optical model lens with thecomputational model eye, (2) modifying the design of the optical modellens on the basis of said visual performance information to improvecorrections of the aberrations of the eye of the individual, andrepeating steps (1) and (2) until visual performance of a modifieddesign of the optical model lens is optimized; and (d) a mechanicaldesign module for generating a CAD output file containing parameters formaking said customized ophthalmic lens or said ophthalmic lens capableof correcting high order aberrations, based on an optimized opticalmodel lens.

Preferably, the lens designing system further comprises a sensor system,which determines a set of characteristic data of an eye of anindividual. A sensor system preferably comprises a wavefront sensor.More preferably, the computer system further comprises a signal modulefor converting said CAD output file into control signals that controlthe computer-controllable manufacturing device to produce saidophthalmic lens.

Another preferred embodiment of the invention is a method for producinga customized ophthalmic lens, the method comprising: (1) designing theophthalmic lens according to the above designing method of the presentinvention; (2) generating control signals that control a computercontrollable manufacturing device; and (3) producing said ophthalmiclens.

A computer controllable manufacturing device is a device that can becontrolled by a computer system and that is capable of producingdirectly an ophthalmic lens or an optical tool for producing anophthalmic lens. Any known, suitable computer controllable manufacturingdevice can be used in the invention. Exemplary computer controllablemanufacturing devices includes, but are not limited to, lathes, grindingand milling machines, molding equipments, and lasers. Preferably, acomputer controllable manufacturing device is a two-axis lathe with a45o piezo cutter or a lathe apparatus disclosed by Durazo and Morgan inU.S. Pat. No. 6,122,999, herein incorporated by reference in itsentirety.

In a preferred embodiment, the step (2) is performed by a system thatcan convert a CAD output file into computer controlling signals.

Another preferred embodiment of the invention is a system forfabricating a customized ophthalmic lens or an ophthalmic lens capableof correcting high order aberrations, comprising:

(1) a computer-controllable manufacturing device and

(2) a computer system comprising:

a model eye design module for creating a computational model eye thatreproduces aberrations of an eye of an individual, wherein thecomputational model eye comprises a lens-supporting surface having thecorneal topography of the eye of the individual and a model retinahaving a curvature of the human retina and a model fovea comprising alattice of pixels that represent photoreceptors, wherein the distancebetween the model fovea and the center of the lens-supporting surface isequal to the visual axial length of the human eye, an optical designmodule for designing an optical model lens to compensate for thewavefront aberrations of the eye of the individual and to accommodatethe corneal topography of the eye of the individual,a lens-designing optimization module for performing an iterativeoptimization process comprising the steps of (i) determining visualperformance information of the optical model lens with the computationalmodel eye, (ii) modifying the design of the optical model lens on thebasis of said visual performance information to improve corrections ofthe aberrations of the eye, and (iii) repeating steps (i) and (ii) untilvisual performance of a modified design of the optical model lens isoptimized,a mechanical design module for generating a CAD output file containingparameters for making said ophthalmic lens, based on an optimizedoptical model lens,a signal module for converting said CAD output file into control signalsthat control the computer-controllable manufacturing device to producesaid ophthalmic lens, anda manufacturing control module for controlling the computer-controllablemanufacturing device to produce said ophthalmic lens.

Preferably, the system for fabricating a customized ophthalmic lensfurther comprises a sensor system, which can determine the aberrationsof the eye and the corneal topography of the eye under control of acomputer system. More preferably, the system for fabricating acustomized ophthalmic lens further comprises an optical metrology systemfor characterizing the fabricated ophthalmic lens.

FIG. 1 is the schematic representation of a system for designing andproducing a customized ophthalmic lens according to a preferredembodiment of the present invention. The system of the present invention100 includes a sensor system 110 that measures a set of characteristicdata of an eye 12 of an individual including at least wavefrontaberrations, corneal topography, and visual axial length. The set ofcharacteristic data of the eye 12 are provided to a computer 120. Thecomputer 120 designs a computational model eye on the basis of the setof characteristic data and an optical model lens to compensate foraberrations of the eye 12. The visual performance of the optical modellens is evaluated by the computer 120 with a computational model eye asshown in FIG. 3 or FIG. 4. The computer 120 redesigns an optimizedoptical model lens which is served as the basis for designing anophthalmic lens 14 and generates a CAD output file containing parametersof the ophthalmic lens 14. The computer 120 then converts the CAD outputfile into control signals for a lathe 134, which then cuts theophthalmic lens 14 or an insert for a mold for the ophthalmic lens 14that would correct any aberrations of the eye 12. One example of asuitable lathe 134 would be a two-axis lathe with a 45o piezo cutter.

Once the lens 14 is cut by the lathe 134, the optical properties of thelens 12 are measured by an optical metrology system 138, as shown inFIG. 5, that generates metrology data of the lens 14, this metrologydata is compared to a digital model of the optimized optical model lensto determine deviation of the actual lens 14 from the optimized opticalmodel lens. The computer 120 calculates necessary corrections to thecontrol signals to the lathe 134 and a new lens 14 is cut. This processcontinues in a closed loop until the actual lens 14 matches the optimaloptical model lens within a suitable tolerance.

The process is shown in greater detail in FIG. 2. The wavefront sensor110 measures the optical properties of the eye 12 and generates datathat is transmitted to an interface 212, that is a resident program inthe computer 120. The interface 212 generates a higher order polynomialfunction that describes the set of characteristic data of the eye 12.This information is fed into an optical computer aided design (CAD)module 218. One suitable example of an optical CAD design module is ASAPwith the input from ZEMAX.

The lens design module 218 is used to design an optical model lens thevisual performance of which is evaluated by an optical analysis module220 comprising a computational model eye (FIG. 3 or FIG. 4) generated onthe basis of the set of characteristic data of the eye 12. The result ofvisual performance is fed back to the optical CAD design module 218 toredesign an optimized optical model lens. The optical analysis module220 is capable of performing ray tracing functions that incorporate ahigher order polynomial description of the model lens. An IGES(International Graphics Exchange System) translating module 222translates the resultant data from the optical analysis module 220 intoa format that may be used by a mechanical CAD module 214. One suitableexample of a mechanical CAD module 214 is PRO/ENGINEER.

The mechanical CAD module 214 also receives data from a start part 216and/or from a set of family tables 228 that provide data relative tosuch parameters as: shrinkage, base curves, center thickness and powerrange. Stock keeping unit (SKU) data 226 provides the mechanical CADmodule 214 with data that describes the type of lens being made andIGES/DXF data 224 provides information regarding the drawing format forthe model lens.

The mechanical CAD module 214 generates design data, which is sent to apost processor and Computer Aided Manufacturing (CAM) module 232. TheCAM module 232 generates the signals that control the lathe 134. Thelens 14 is made by the lathe 134 and is analyzed by the metrology system138, which generates metrology data 240 that the mechanical CAD module214 uses in subsequent iterations of the design process.

FIGS. 6A to 6C show a flow diagram of a process to produce a customizedophthalmic lenses according to a preferred embodiment of the invention.In step 601, a set of characteristic data of an eye of a patient isprovided to a computer system. The set of characteristic data includingwavefront aberrations and corneal topography data is served as the basisfor creating a computational model eye in step 602. In step 603, ifthere is a need for correcting presbyopia, the computer system continuesat step 604, else the computer system goes to step 605. In step 604, theoptical design parameters, such as pupil diameter range,alternating/simultaneous function, monocular/binocular function, segmentdesign (such as shape and number of zones, discrete/progressive zones,lens added power, etc.), and ages and occupational factors of thatindividual, are provided to the computer system or retrieved from adatabase. In step 605, if a special shape of the posterior surface ofthe customized contact lens is required, the computer system continuesat step 606, else the computer system goes to step 607. In step 606, aspecial shape of the posterior surface of the customized contact lens isdesigned. In step 607, if the customized contact lens needs orientationfeatures required for astigmatism, the computer system continues at step608, else the computer system goes to step 609. In step 608, theorientation features are designed by the computer system. Any known,suitable orientation features can be used. Exemplary orientationfeatures include, but are not limited to, a prism ballast or the likethat uses a varying thickness profile to control the lens orientation, afaceted surface in which parts of the lens geometry are removed tocontrol the lens orientation, a ridge feature which orients the lens byinteracting with the eyelid. In step 609, an anterior surface isdesigned and the visual performance of the designed lens is evaluated instep 610 with the computational model eye generated in step 602. In step611, if the visual performance of the designed lens is optimized, thecomputer system continues at step 612, else the computer system goesback to step 609 where the lens design is modified. In step 612, thecomputer system queries a database that contains a plurality of SKUs ofcustomized contact lens. In step 613, if a best-match is located, thecustomized contact lens can be delivered, else the computer systemcontinues at step 614, where a new lens SKU is created and entered inthe database. In step 615, the computer system converts the opticaldesign into a mechanical design and then generates control signals thatcontrol a computer-controllable manufacturing device to produce thecustomized contact lens in step 616.

Another preferred embodiment of the invention is an optical metrologysystem for characterizing an ophthalmic lens. FIG. 5 is a schematicrepresentation of an optical metrology system according to a preferredembodiment of the present invention. The optical metrology system 138 ofthe present invention comprises a monochromatic point light source 501and an aperture 510 which is served as a simulated fovea. Themonochromatic light from the light source 501 passes through theaperture 510 and illuminates onto a diffraction limited model eye 520.In an alternative preferred embodiment, the model eye 520 can be arefractive optics (1) having a power of refraction equal to the overallpower of refraction of the human eye or of an eye of an individual, or(2) having a power of refraction of the human cornea or of a cornea ofan individual, depending on whether a contact lens or an intraocularlens (IOL) is under test. The front surface of the model eye 520 has atypical topography of the human cornea or a topography for accommodatinga specific corneal topography of an individual. A contact lens 10 ismounted on the model eye 520 and lubricated by a lubricating system 515which generates a simulated tear film between the contact lens 10 andthe model eye 520. The contact lens 10 generates wavefront aberrationswhich are measured by a wavefront sensor 550. The simulated fovea 510 iscapable of moving along the light path via manual means or via aprecision motion control system to null defocus. An IOL can be placedbetween the model eye and the model fovea and its exact position isdefined by an optical axial distance of 7.68 mm from the posteriorsurface of the IOL to the aperture 510.

The monochromatic point light source 501 preferably is a laser. Byplacing the simulated fovea 510 at the focal point, the metrology systemof the present invention is capable of determining wavefront aberrationscaused by the ophthalmic lens mounted on the diffraction limited modeleye. Any discrepancy between the wavefront aberrations of an eye of anindividual and the wavefront aberrations of the ophthalmic lens undermetrology test will point out errors in the production of the ophthalmiclens and can provide instructions how to adjust control signals thatcontrol the cutting lathe. One of the unique features of the metrologysystem of the present invention is its capability to characterize aspecific area of the lens by focusing the detection of the wavefrontsensor in that area.

Preferably, the optical metrology system further comprises a pupil withadjustable size that is located between the model eye and the wavefrontsensor.

More preferably, the optical metrology system further comprises amicro-electro-mechanical device (MEM) that can be controlled by acomputer system so that the combination of the model eye and MEMreproduces the wavefront aberrations of an eye of an individual. The MEMis located in the optical pathway of the metrology system between thewavefront sensor and the model eye. When an ophthalmic lens is installedin such optical metrology system, any residual aberrations arereflective of the quality of the ophthalmic lens. Any known, suitableMEMs can be used in the invention. One example of MEMs is a programmablemirror array.

Another preferred embodiment of the invention is a method forcharacterizing the optical metrology of an ophthalmic lens, comprisingthe steps of:

(1) determining first wavefront aberrations before the ophthalmic lensis installed in an optical metrology system which comprises:

(a) a monochromatic point light source;

(b) a diffraction limited model eye in front of said light source,wherein said model eye has a posterior surface and an opposite anteriorsurface having an averaged corneal topography of a population;

(c) a lubricating system to simulate a tear film on the anterior surfaceof the model eye;

(d) an aperture which simulates the human fovea and is located betweensaid light source and said model eye, wherein said simulated fovea iscapable of moving along the light path via manual means or via aprecision motion control system to null defocus; and(e) a wavefront sensor in front of said model eye;(2) installing said ophthalmic lens in the optical metrology system;(3) determining second wavefront aberrations derived from the opticalmetrology system having the ophthalmic lens emplaced therein; and(4) obtaining third wavefront aberrations by subtracting the firstwavefront aberrations from the second wavefront aberrations, wherein thethird wavefront aberrations are contributed by the ophthalmic lens.

Any ophthalmic lens which passes the optical metrology test should havewavefront aberrations that compensate for the wavefront aberrations ofthe eye of an idividual to the extent according to its optical design.

The ophthalmic lens can be a contact lens or an intraocular lens. Wherethe ophthalmic lens is a contact lens, the contact lens is mounted onthe model eye which has a power of refraction equal to an averaged powerof refraction of eyes of a population and there is a tear film betweenthe posterior surface of the contact lens and the anterior surface ofthe model eye.

Where the ophthalmic lens is a phakic intraocular lens, the phakicintraocular lens is mounted on the model eye which has a power ofrefraction equal to an averaged power of refraction of eyes of apopulation and the phakic intraocular lens is placed at a positionbetween the model eye and the aperture.

Where the ophthalmic lens is an aphakic intraocular lens, the model eyeis a model cornea having a power of refraction equal to an averagedpower of refraction of corneas of a population and the intraocular lensis placed at a position between the model eye and the aperture.Preferably, the distance from the posterior surface of the aphakicintraocular lens to the aperture is equal to 7.68 mm.

In another preferred embodiment, the present invention provides a methodfor characterizing the optical metrology of an ophthalmic lens,comprising the steps of:

(1) determining first wavefront aberrations before installing saidophthalmic lens in an optical metrology system which comprises:

(a) a monochromatic point light source;

(b) a diffraction limited model eye in front of said monochromatic pointlight source, wherein said model eye has an anterior surface having atypical topography of the human cornea or a topography for accommodatinga specific corneal topography of an eye of an individual;(c) a lubricating system to simulate a tear film on the model eye;(d) a simulated fovea which is located between said light source andsaid model eye, wherein said simulated fovea is capable of moving alongthe light path via manual means or via a precision motion control systemto null defocus;(e) a wavefront sensor in front of said model eye, wherein saidwavefront sensor is capable of measuring wavefront aberrations caused bysaid contact lens; and(f) a computer-controllable MEM which is located between the model eyeand the wavefront sensor, wherein the computer-controllable MEMgenerates desired wavefront aberrations of the eye which needs to becorrected;(2) installing the ophthalmic lens in the optical metrology system; and(3) determining second wavefront aberrations derived from the opticalmetrology system having the ophthalmic lens emplaced therein; and(4) obtaining third wavefront aberrations by subtracting the firstwavefront aberrations from the second wavefront aberrations, wherein thethird wavefront aberrations are uncorrectable wavefront aberrations ofthe eye with the ophthalmic lens or additional undesired aberrationscontributed by the ophthalmic lens.

The above lens-designing and fabricating methods and systems and themetrology method and system of the present invention can find use inmanufacturing customized ophthalmic lenses. The method for manufacturingcustomized ophthalmic lenses comprises the steps of:

(1) analyzing eyes of each of individuals from a population to obtain aset of characteristic data comprising aberrations and cornealtopography;

(2) compiling population statistics of aberrations and cornealtopographies;

(3) creating a plurality of computational model eyes each representingone of a plurality of nominal segments of the population, based on anaveraged aberrations and an averaged cornea topography for this nominalsegment of the population;

(4) designing a plurality of optical model lenses each of whichaccommodates the averaged corneal topography of one of the plurality ofnominal segment of the population and corrects the averaged aberrationsof the corresponding nominal segment of the population;(5) optimizing designs of the plurality of the optical model lenses withone of the plurality of the computational model eyes;(6) transforming the plurality of the optimized optical model lensesinto a plurality sets of mechanical parameters each for making onecontact lens;(7) creating one stock keeping unit (SKU) for each of each of thecontact lenses; and(8) manufacturing said ophthalmic lenses having a specific SKU.

A SKU can contain information for identifying a specific ophthalmic lensand for manufacturing this specific ophthalmic lens. Preferably, a SKUcomprises wavefront aberrations and a corneal topography representing anominal segment of a population. The wavefront aberrations and thecorneal topography can be quantified in any forms, preferably inweighted polynomials. More preferably, the wavefront aberrations and thecorneal topography are quantified in one identical form. Much morepreferably, the wavefront aberrations and the corneal topography arequantified in Zernike polynomials plus spline-based mathematicalfunctions. The Zernike polynomials can have at least second order modes,preferably at least third order modes, and more preferably at leastfifth order modes. More preferably, a SKU further comprises at least amember selected from the group consisting of lens material, shrinkage,non-optical edge zone and its curvature, center thickness, bevel,lenticular, and edge.

Together with a communication network, such as the Internet, the abovemethods and systems for designing/fabricating a customized ophthalmiclens and for manufacturing customized ophthalmic lenses are conducive toconducting electronic business involving ordering and delivering ofcustomized lenses.

The Internet comprises a vast number of computers and computer networksthat are interconnected through communication links. The interconnectedcomputers exchange information using various services, such aselectronic mail, Gopher, and the World Wide Web (“WWW”). The WWW serviceallows a server computer system (i.e., Web server or Web site) to sendgraphical Web pages of information to a remote client computer system.The remote client computer system can then display the Web pages. Eachresource (e.g., computer or Web page) of the WWW is uniquelyidentifiable by a Uniform Resource Locator (“URL”). To view a specificWeb page, a client computer system specifies the URL for that Web pagein a request (e.g., a HyperText Transfer Protocol (“HTTP”) request). Therequest is forwarded to the Web server that supports that Web page. Whenthat Web server receives the request, it sends that Web page to theclient computer system. When the client computer system receives thatWeb page, it typically displays the Web page using a browser. A browseris a special-purpose application program that effects the requesting ofWeb pages and the displaying of Web pages.

Currently, Web pages are typically defined using HyperText MarkupLanguage (“HTML”). HTML provides a standard set of tags that define howa Web page is to be displayed. When a user indicates to the browser todisplay a Web page, the browser sends a request to the server computersystem to transfer to the client computer system an HTML document thatdefines the Web page. When the requested HTML document is received bythe client computer system, the browser displays the Web page as definedby the HTML document. The HTML document contains various tags thatcontrol the displaying of text, graphics, controls, and other features.The HTML document may contain URLs of other Web pages available on thatserver computer system or other server computer systems.

FIG. 7 is a block diagram illustrating a preferred embodiment of theinvention. This preferred embodiment provides a method for placing anorder of a customized ophthalmic lens over the Internet using the WorldWide Web.

Referring to FIG. 7, a server system 710 comprises a server engine 711,a lens design engine 713, a query engine 712, a metrology engine 714(optional), a client identifier table 722, various Web pages 721, apatient database 731, an eye-care practitioner database 732, an SKUdatabase 733, an order database 734, and an inventory database 735.

The server engine 711 receives HTTP requests to access Web pagesidentified by URLs and provides the Web pages to the various clientsystems. The server engine also assigns and sends a client identifier toa client computer system once when the client computer system firstinteracts with the server system. From then on, the client computersystem includes its client identifier with all messages sent to theserver system so that the server system can identify the source of themessage.

The lens design engine 713 is a computer program that implements theabove-described method for designing a customized ophthalmic lens. Thelens design engine designs a pair of ophthalmic lenses on the basis ofthe wavefront aberrations and corneal topographies of the eyes of anindividual and generates a set of physical and optical parameters forthis pair of ophthalmic lenses optimized for accommodating the cornealtopographies and for correcting aberrations. Such set of physical andoptical parameters can be used to produce a new pair of customizedlenses or be utilized by the query engine 712, that is a computerprogram, to search against a SKU database. The query engine employs analgorithm to find for each of the two eyes a list of SKUs each of whichcan adequately accommodate the corneal topography of that eye andadequately correct the aberrations of that eye. Such lists of SKUs withlens information, such as the conformity of each lens to the cornealtopography of the corresponding eye and a reachable visual acuity with aspecific SKU. Preferably, the conformity of each lens to the cornealtopography of the corresponding eye is displayed in a client computersystem as an interactive three-dimensional graphic representation andthe reachable visual acuity with a specific SKU is displayed in the samecomputer system as a graphic representation, for example, a simulatedretina image quality.

“A contact lens can correct adequately the aberrations of an eye”, asused herein, means that the lens can correct the aberrations of the eyeat least to the extent as prescribed by an eye-care practitioner.

The metrology engine 714 is a computer program that is able tocharacterize the optical metrology of an ophthalmic lens identified by aSKU identifier using the computer model eye created by the lens designengine 713. The metrology engine determines the visual performance ofthat ophthalmic lens and estimates the visual acuity of an eye with thatophthalmic lens.

The patient database 731 contains patient-specific order information,such as name of the patient, billing information, and shippinginformation, for various patients or potential patients.

The eye-care practitioner database 732 contains eye-carepractitioner-specific order information, such as name of the patientunder the eye-care practitioner's care, and address and contactinformation of the eye-care practitioner, for various patients orpotential patients.

The SKU database 733 contains descriptions and identifiers of SKUs ofvarious ophthalmic lenses that have been and can be produced.

The order database 734 contains an entry for each order that has not yetbeen shipped to a patient or an eye-care practitioner.

The inventory database 735 contains SKU identifiers of ophthalmic lensesthat are currently in stock.

The client identifier table 722 contains a mapping from each clientidentifier, which is a globally unique identifier that uniquelyidentifies a client computer system, to the patient or eye-carepractitioner last associated with that client computer system.

The client computer system 740 comprises a browser 741, an assignedclient identifier 745, and input/output (I/O) interface devices 742. Theclient identifier is stored in a file, referred to as a “cookie.” Aninput device receives input (such as data, commands, etc.) from humanoperators and forwards such input to the client computer system 740 viaa communication medium. Any known, suitable input device may be used inthe present invention, such as a keyboard, pointing device (mouse,roller ball, track ball, light pen, etc.), touch screen, etc. User inputmay also be stored and then retrieved, as appropriate, from data/commandfiles. An output device outputs information to human operators. Theclient computer system transfers such information to the output devicevia a communication medium. Any well known, suitable output device maybe used in the present invention, such as a monitor, a printer, a floppydisk drive, a text-to-speech synthesizer, etc. In a more preferredembodiment, a sensor system, that can measure at least wavefrontaberrations, preferably at least wavefront aberrations and cornealtopography of the eyes of an individual, is connected to the clientcomputer system via a communication medium.

The client computer system may comprise any combination of hardware andsoftware that can interact with the server system. One example is aclient computer system comprising a television-based system.

It will be understood that the method of the invention for ordering apair of customized lenses can be implemented in various environmentsother than the Internet. Exemplary environments other than the Internetinclude, but are not limited to, an electronic mail environment, localarea network, wide area network, and point-to-point dial up connection.

There are some advantages associated with the lens-ordering system andmethod of the invention. One advantage is that measurements of thevision conditions of the eyes of a patient can be fast and accurate.Another advantage is that a patient will have the choice to select apair of ophthalmic lenses that gives him a desired visual acuity andwearer's comfort. With the lens-ordering system and method of theinvention, it may be possible to set up an eye examination/order stationin a public area, such as a shopping mall. Patients can have their eyesexamined and order pairs of ophthalmic lenses.

Another preferred embodiment of the invention is a system for examiningthe eyes of an individual and ordering a pair of customized contactlenses, the system comprising:

(1) a sensor system that determines a set of characteristic datacomprising wavefront aberrations and corneal topography data of a firstand a second eye of the patient, wherein the sensor system is connectedthrough a communication media to a client computer system;(2) the client computer system comprising:(i) a customer identifier that identifies the client computer system apatient and/or an eye-care practitioner is using to connect to a serversystem;(ii) a sending/receiving means for: (a) sending a first request to theserver system to look for a pair of contact lenses capable of correctingthe aberrations of both eyes, the first request including the set ofcharacteristic data of the first and second eyes so that the serversystem can compile and supply lens information related to a first listand a second list of SKUs, wherein each of the first list of SKUs has aposterior surface adequately accommodating the corneal topography of thefirst eye and can correct adequately the aberrations of the first eye,and wherein each of the second list of SKUs has a posterior surfaceadequately accommodating the corneal topography of the second eye andcan correct adequately the aberrations of the second eye; and (b)receiving the lens information;(iii) a displaying means for displaying lens information that helps apatient to select a pair of customized lenses; and(iv) a selecting means for selecting a pair of SKUs identified by afirst SKU identifier and a second SKU identifier or a new pair ofcustomized contact lenses and for sending a second request to the serversystem to order the pair of SKUs or the new pair of customized contactlenses to be made, along with the customer identifier so that the serversystem can locate additional information to complete and fulfill theorder.

Preferably, sets of characteristic data of eyes further comprise visualaxial length. More preferably, sets of characteristic data of eyes aredetermined at various pupil sizes.

Preferably, lens information comprises the conformity of each lens tothe corneal topography of the corresponding eye and a reachable visualacuity with a specific SKU. The conformity of each lens to the cornealtopography of the corresponding eye preferably is displayed in a clientcomputer system as an interactive three-dimensional graphicrepresentation. The reachable visual acuity with a specific SKUpreferably is displayed in the same computer system as a graphicrepresentation, more preferably a graphics representing a simulatedretina image quality.

1. A method for designing a customized ophthalmic lens, the methodcomprising the steps of: (1) providing a set of characteristic data ofan eye of an individual, wherein said set of characteristic datacomprises wavefront aberrations of the eye and corneal topography; (2)creating a computational model eye that reproduces the wavefrontaberrations of the eye of the individual, wherein the computationalmodel eye comprises a lens-supporting surface having the cornealtopography of the eye of the individual and a model retina having amodel fovea comprising a lattice of pixels that represent photoreceptorsand can be used to perform bitmap image analysis and/or ghost imageanalysis of an optical model lens to be evaluated, wherein the distancebetween the model fovea and the center of the lens-supporting surface isequal to a visual axial length of the human eye; (3) designing anoptical model lens which is capable of compensating for the wavefrontaberrations of the eye, wherein said optical model lens has an anteriorsurface and an opposite posterior surface; (4) evaluating the visualperformance of said optical model lens with the computational model eye;(5) obtaining visual performance information of said optical model lens;(6) modifying the design of said optical model lens on the basis of saidvisual performance information to improve corrections of the aberrationsof the eye, if the visual performance of said optical model lens is notoptimal; (7) repeating steps (4) to (6), if necessary, until the visualperformance of said optical model lens is optimal; and (8) transformingthe optimized optical model lens into a set of mechanical parameters formaking said customized ophthalmic lens.
 2. A method of claim 1, whereinthe customized ophthalmic lens is a contact lens.
 3. A method of claim2, wherein the computational model eye is: (1) a reduced computationalmodel eye that comprises an optical refractive element having a firstoptical surface and an opposite second optical surface and the modelretina, wherein the first optical surface is the lens supportingsurface; or (2) an anatomical computational model eye that comprises amodel cornea having an anterior surface and an opposite posteriorsurface, a model crystalline lens, and the model retina, wherein theanterior surface of the model cornea is the lens-supporting surface,wherein the model cornea, the model crystalline lens and the modelretina are arranged in a way identical to the arrangement of theircorresponding optical elements in the human eye.
 4. A method of claim 1,wherein the customized ophthalmic lens is an intraocular lens.
 5. Amethod of claim 3, wherein the computational model eye is an anatomicalcomputational model eye that comprises a model cornea having an anteriorsurface and an opposite posterior surface, a model crystalline lens, andthe model retina, wherein the anterior surface of the model cornea isthe lens-supporting surface, wherein the model cornea, the modelcrystalline lens and the model retina are arranged in a way identical tothe arrangement of their corresponding optical elements in the humaneye.
 6. A method for designing a customized ophthalmic lens, comprisingthe steps of: (1) providing a set of characteristic data of an eye of anindividual, wherein said set of characteristic data comprises wavefrontaberrations of the eye and corneal topography; (2) creating acomputational model eye that reproduces the wavefront aberrations of theeye of the individual, wherein the computational model eye comprises alens-supporting surface having the corneal topography of the eye of theindividual and a model retina having a model fovea comprising a latticeof pixels that represent photoreceptors, wherein the distance betweenthe model fovea and the center of the lens-supporting surface is equalto a visual axial length of the human eye, wherein the computationalmodel eye is (a) a reduced computational model eye that comprises anoptical refractive element having a first optical surface and anopposite second optical surface and the model retina, wherein the firstoptical surface is the lens supporting surface, or (b) an anatomicalcomputational model eye that comprises a model cornea having an anteriorsurface and an opposite posterior surface, a model crystalline lens, andthe model retina, wherein the anterior surface of the model cornea isthe lens-supporting surface, wherein the model cornea, the modelcrystalline lens and the model retina are arranged in a way identical tothe arrangement of their corresponding optical elements in the humaneye, wherein the computational model eye further comprises a model pupilwhich is located between the optical refractive element and the modelretina in the reduced computational model eye or between the modelcornea and the model crystalline lens in the anatomical model eye,wherein the size of the model pupil is about from 2.0 mm to 8.0 mm andadjustable according to the individual's age and/or illumination lightintensity; (3) designing an optical model lens which is capable ofcompensating for the wavefront aberrations of the eye, wherein saidoptical model lens has an anterior surface and an opposite posteriorsurface; (4) evaluating the visual performance of said optical modellens with the computational model eye; (5) obtaining visual performanceinformation of said optical model lens; (6) modifying the design of saidoptical model lens on the basis of said visual performance informationto improve corrections of the aberrations of the eye, if the visualperformance of said optical model lens is not optimal; (7) repeatingsteps (4) to (6), if necessary, until the visual performance of saidoptical model lens is optimal; and (8) transforming the optimizedoptical model lens into a set of mechanical parameters for making saidcustomized ophthalmic lens.
 7. A method of any one of claim 6, whereinthe size of the fovea is about 2 mm.
 8. A method of any one of claim 7,wherein the lattice of pixels is a hexagonal lattice of pixels with adiameter of about 2.5 micron.
 9. A method of claim 8, wherein theposterior surface of said optical model lens accommodates the cornealtopography of the eye of the individual.
 10. A method of claim 9,wherein each of the anterior surface and posterior surface of theoptical model lens is quantified by a mathematical description.
 11. Amethod of claim 10, wherein the mathematical description comprises oneore more mathematical functions selected from the group consisting ofconic functions, quadric functions, polynomials of any degree, Zernikepolynomials, exponential functions, trigonometric functions, hyperbolicfunctions, rational functions, Fourier series, and wavelets.
 12. Amethod of claim 11, wherein the mathematical description comprisesZernike polynomials.
 13. A method of claim 12, wherein the mathematicaldescription further comprises spline-based mathematical functions.
 14. Amethod of claim 9, wherein the visual performance information comprisesone or more members selected from the group consisting of wavefrontaberrations, point spread function (PSF), line spread function (LSF),modulation transfer function (MTF), phase transfer function, contrastthreshold function, contrast sensitivity function (CFS), bitmap imageanalysis, ghost image analysis, focal length analysis, and optical poweranalysis.
 15. A method of claim 14, wherein the optical design of saidoptical model lens is optimized by using a set of aberrationcoefficients that represent the wavefront aberrations of the eye of theindividual as weighted operands in an optical design optimization loop,on the basis of the visual performance information obtained in step 5.16. A method of claim 14, wherein the optical design of said opticalmodel lens is optimized by using artificial intelligence (AI) programsor neural networks, on the basis of the visual performance informationobtained in step
 5. 17. A method of claim 16, wherein the step oftransforming the optimized optical model lens into a set of mechanicalparameters for making said customized ophthalmic lens is performed bytranslating the design of the optimized optical model lens back andforth between an optical CAD system and a mechanical CAD system using atranslation format which allows a receiving system, either optical CADor mechanical CAD, to construct NURBs or Beizier surfaces of an intendeddesign.
 18. A method of claim 8, wherein the posterior surface of saidoptical model lens accommodates an averaged corneal topography derivedfrom population studies.
 19. A method of claim 6, further comprising thesteps of: (9) converting the set of mechanical parameters for making thelens into control signals that control a computer-controllablemanufacturing device; and (10) producing the lens using the computercontrollable manufacturing device.
 20. A method of claim 19, wherein thecomputer controllable manufacturing device is a computer-controllablelathe.
 21. A method for creating a computational model eye, the methodcomprising the steps of: (1) providing a set of characteristic data ofan eye of an individual, wherein said set of characteristic datacomprises wavefront aberrations and corneal topography data of the eyeof the individual; (2) converting the corneal topography data into amathematical description representing a first surface of a firstrefractive optical element, the first optical refractive element havingthe first surface and an opposite second surface; (3) designing andoptimizing the second surface of the first refractive optical element sothat the first refractive optical element, alone or in combination witha second refractive optical element that has a third surface and anopposite fourth surface and an index of refraction distribution,reproduces the wavefront aberrations of the eye; (4) designing a modelretina that has a curvature of the human retina and comprises a modelfovea having a lattice of pixels representing photoreceptors; and (5)arranging the first refractive optical element and the model retinaalong an optical axis in a way such that the distance between the foveaand the center of the first surface of the first refractive opticalelement is equal to the visual axial length of the human eye, whereinthe size of fovea is about 2 mm and wherein the lattice of pixels is ahexagonal lattice of pixels with a diameter of about 2.5 micron.
 22. Amethod of claim 21, wherein each of the first surface and second surfaceof the first refractive optical element is quantified by a mathematicaldescription.
 23. A method of claim 22, wherein the mathematicaldescription comprises one ore more mathematical functions selected fromthe group consisting of conic functions, quadric functions, polynomialsof any degree, Zernike polynomials, exponential functions, trigonometricfunctions, hyperbolic functions, rational functions, Fourier series, andwavelets.
 24. A method of claim 23, wherein the mathematical descriptioncomprises Zernike polynomials.
 25. A method of claim 24, wherein themathematical description further comprises spline-based mathematicalfunctions.
 26. A method of claim 25, wherein the computational model eyefurther comprises a model pupil which is located between the firstrefractive optical element and the model retina, wherein the size of themodel pupil is about from 2.0 mm to 8.0 mm and adjustable according tothe individual's age and/or illumination light intensity.
 27. A methodof claim 26, wherein the computational model eye comprises a modelcrystalline lens as the second refractive optical element and a modelcorneal as the first refractive optical element, wherein the modelcrystalline lens is constructed on the basis of the crystalline lens ofthe human eye so that the model crystalline lens has a power ofrefraction equal to the power of refraction of the human eye, whereinthe model cornea, the model crystalline lens and the model retina arearranged in a way identical to the arrangement of their correspondingelements in the human eye.
 28. A system for characterizing the opticalmetrology of an ophthalmic lens, the system comprising: (a) amonochromatic point light source; (b) a diffraction limited model eye infront of said monochromatic point light source, wherein said model eyehas a posterior surface and an opposite anterior surface having anaveraged corneal topography of a population; (c) a lubricating system tosimulate a tear film on the anterior surface of the model eye; (d) anaperture which simulates the human fovea and is located between saidlight source and said model eye, wherein said simulated fovea is capableof moving along the light path via manual means or via a precisionmotion control system to null defocus; (e) a wavefront sensor in frontof said model eye; and (f) a micro-electro-mechanical device (MEM) thatis controlled by a computer system to generate desired wavefrontaberrations of the eye which needs to be corrected, wherein the MEM islocated in the optical pathway of the metrology system between thewavefront sensor and the model eye.
 29. A system of claim 28, whereinthe light source is a laser.
 30. A system of claim 29, furthercomprising an additional aperture to simulate the pupil or iris of theeye, wherein the additional aperture is located along the opticalpathway between the wavefront sensor and the refractive optics.
 31. Asystem of claim 30, wherein the ophthalmic lens is a contact lens ismounted on the model eye but separated from the model eye by the tearfilm between the posterior surface of the contact lens and the anteriorsurface of the model eye, wherein the model eye has a power ofrefraction equal to an averaged power of refraction of eyes of apopulation.
 32. A system of claim 30, wherein the ophthalmic lens is anintraocular lens is installed in a position that is between the apertureand the anterior surface of the model eye along the optical axis of themodel eye, wherein the model eye has a power of refraction equal to anaveraged power of refraction of corneas of a population.
 33. A system ofclaim 32, wherein the MEM is deformable mirror.
 34. A system of claim30, wherein the MEM is deformable mirror.
 35. A system of claim 34,further comprising a hardware or software means for limiting a region ofthe ophthalmic lens under test to a specific optical zone.